/*
 * Copyright 2002-2016 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.web.method.annotation;

import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;

import org.springframework.core.MethodParameter;
import org.springframework.http.HttpHeaders;
import org.springframework.lang.Nullable;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;

Resolves Map method arguments annotated with @RequestHeader. For individual header values annotated with @RequestHeader see RequestHeaderMethodArgumentResolver instead.

The created Map contains all request header name/value pairs. The method parameter type may be a MultiValueMap to receive all values for a header, not only the first one.

Author:Arjen Poutsma, Rossen Stoyanchev
Since:3.1
/** * Resolves {@link Map} method arguments annotated with {@code @RequestHeader}. * For individual header values annotated with {@code @RequestHeader} see * {@link RequestHeaderMethodArgumentResolver} instead. * * <p>The created {@link Map} contains all request header name/value pairs. * The method parameter type may be a {@link MultiValueMap} to receive all * values for a header, not only the first one. * * @author Arjen Poutsma * @author Rossen Stoyanchev * @since 3.1 */
public class RequestHeaderMapMethodArgumentResolver implements HandlerMethodArgumentResolver { @Override public boolean supportsParameter(MethodParameter parameter) { return (parameter.hasParameterAnnotation(RequestHeader.class) && Map.class.isAssignableFrom(parameter.getParameterType())); } @Override public Object resolveArgument(MethodParameter parameter, @Nullable ModelAndViewContainer mavContainer, NativeWebRequest webRequest, @Nullable WebDataBinderFactory binderFactory) throws Exception { Class<?> paramType = parameter.getParameterType(); if (MultiValueMap.class.isAssignableFrom(paramType)) { MultiValueMap<String, String> result; if (HttpHeaders.class.isAssignableFrom(paramType)) { result = new HttpHeaders(); } else { result = new LinkedMultiValueMap<>(); } for (Iterator<String> iterator = webRequest.getHeaderNames(); iterator.hasNext();) { String headerName = iterator.next(); String[] headerValues = webRequest.getHeaderValues(headerName); if (headerValues != null) { for (String headerValue : headerValues) { result.add(headerName, headerValue); } } } return result; } else { Map<String, String> result = new LinkedHashMap<>(); for (Iterator<String> iterator = webRequest.getHeaderNames(); iterator.hasNext();) { String headerName = iterator.next(); String headerValue = webRequest.getHeader(headerName); if (headerValue != null) { result.put(headerName, headerValue); } } return result; } } }